A compressor includes a housing having a suction inlet, at least one economizer inlet, and an outlet. A first cylinder arranged within the housing includes a first suction valve arranged in fluid communication with the suction inlet and a first discharge valve fluidly connected to the outlet. At least one second cylinder is arranged within the housing. The at least one second cylinder has a second suction valve in fluid communication with the at least one economizer inlet and a second discharge valve fluidly connected to the outlet. A first piston is arranged within the first cylinder and a second piston is arranged within the at least one second cylinder.

Refrigerant compressor with a hermetically sealed housing and a drive unit in the interior of the housing. At least one damping element is in the housing is connected to the drive unit. The damping element has three contact areas separated from each other by an edge, in which in a first deflected state of the drive unit a first contact area contacts a first inner surface area of the housing, wherein in a second deflected state a second contact area contacts a second inner surface area of the housing, but the first contact area does not contact the first inner surface area, wherein in a third deflected state of the drive unit a third contact area contacts a third inner surface area, but the first and second contact areas do not contact the first and second inner surface areas, respectively.

A refrigerant compressor group for a refrigeration system, comprising at least two piston compressors that operate in parallel between a common low-pressure connector and a common high-pressure connector, wherein, for the purpose of adjusting it to different requirements, it is provided, in a refrigerant compressor group, for a variable overall mass flow throughput in the refrigerant compressor group to be adjustable in that, in the case of at least one of the piston compressors, its mass flow throughput is adjustable by speed selection with the aid of a frequency converter for the electric motor, and in that, in the case of at least one of the piston compressors, its mass flow throughput is adjustable by cylinder selection, and in that an operating condition controller for the refrigerant compressor group is provided which, on the basis of a performance request signal of the refrigeration system that is transmitted to the operating condition controller, controls the overall mass flow throughput by open or closed-loop control by predetermining the cylinder selection and the speed selection.

A linear compressor or sealed system may include a casing, a piston, an driving coil, an inner back iron assembly, and a planar spring assembly. The casing may include a cylinder assembly defining a chamber along an axial direction. The piston may be slidably received within the chamber of the cylinder assembly. The inner back iron assembly may be positioned in the driving coil. The planar spring assembly may be mounted to the inner back iron assembly. The planar spring assembly may include a first planar spring, a second planar spring axially spaced apart from the first planar spring, and a polymer shim layer disposed between at least a portion of the first planar spring and the second planar spring.

Refrigerant compressor for refrigeration systems, comprising an electric motor, at least two cylinder banks and a mechanical performance control unit for activating and deactivating at least one of the cylinder banks in order to activate or deactivate its refrigerant output, wherein, for the purpose of operation in partial performance conditions, the refrigerant compressor is operable in at least two different operating modes, of which each provides an activation or deactivation of the cylinder banks that is different from the other operating modes, wherein associated with the refrigerant compressor is a frequency converter for controlling the speed of the electric motor, wherein associated with the refrigerant compressor is an operating condition controller that, in accordance with a performance request signal supplied to it for operation of the refrigerant compressor in the partial performance condition corresponding to this performance request signal, operates the refrigerant compressor in an operating mode that is selected from at least two different operating modes and at a speed adapted to the selected operating mode, for the purpose of achieving this partial performance condition.

A positive displacement machine includes a case including a tubular guide part in which a pressure chamber is provided, a slide member including a shaft extending in a first direction and a piston provided at an end portion of the shaft and disposed in the guide part, a coupling member coupled to the slide member and extending in a second direction intersecting the first direction, a first rotating member coupled to one end of the coupling member and configured to rotate around a first rotation axis extending in the second direction, and a rocking absorbing mechanism configured to absorb a rocking motion of the piston around an axis extending in the first direction. The rocking absorbing mechanism is provided between the coupling member and the slide member, between the shaft and the piston, or between the piston and an inner wall of the guide part.

Techniques are disclosed for systems and methods to reduce the overall physical size of and mechanical vibrations within a cryocooler/refrigeration system configured to provide cryogenic and/or general cooling of a device or sensor system. A refrigeration system includes an annular linear compressor configured to generate a compression wave of working gas for the system. The annular linear compressor includes an annular cylinder head with a pressure plate and a neck protruding from one side of the annular cylinder head, a compressor housing configured to mate with the pressure plate and the neck of the annular cylinder head and form a sealed cavity therebetween, and an annular cylinder assembly disposed within the sealed cavity and about the neck of the annular cylinder head. The annular cylinder assembly includes an annular piston assembly disposed within an annular cylinder of the annular cylinder assembly.

The present invention relates to a system and method for operational acoustic optimization of a variable speed compressor (2) comprising a synchronous motor (6), a frequency inverter (3) and a control block (5), such optimization being carried out by modifying the switching frequency of the supply signal (9) of the motor (6) contained in the compressor (2), via a control block (5), only during the aligmnent phase of the motor (6), thus, not impairing the performance of the compressor (2), the thermal management of the inverter (3) and the acoustic performance of the system.

A fluid pump for pumping a fluid. One or more piston-cylinder arrangements each include a respective cylinder portion, a respective head portion and a respective piston portion together defining a respective pumping chamber. One or more connecting arrangements connect a crank member to the one or more piston-cylinder arrangements to drive the respective piston portion of each of the one or more piston-cylinder arrangements. A housing and the respective piston portion of each of the one or more piston-cylinder arrangements together house the crank member in an interior. The interior is sealed to capture blow-by. A transmission is arranged to transmit power, for rotating the crank member, into the housing magnetically, electrically or both.

A compressor unit of a refrigeration device includes a compression chamber. A piston is configured to be moved back and forth along an axis to alternately compress and decompress a gas in the chamber. An electromagnetic actuator is configured to drive the piston and includes a stator assembly with a driving coil that is coaxial with the axis and two permanent ring magnets that are radially magnetized identically to one another in a plane that is perpendicular to the axis. The ring magnets are located on opposite sides of the driving coil along the axis. A ferromagnetic shaft is elongated parallel to the axis and connected to the piston. When an alternating electrical current flows through the coil, the shaft is magnetized such that the shaft is alternately attracted to one of the ring magnets and repelled by the other to drive the piston back and forth.